The fortification of the exterior is a feature of almost universal occurrence in the churches of the South, as has been already noticed, and we shall meet with other instances. This peculiar characteristic probably dates from the time of the crusades against the Albigenses in the twelfth and thirteenth centuries, when the inhabitants were glad to adopt every means in their power to obtain protection, and had to turn even their churches, which were not sacred in the eyes of their assailants, into fortresses for their defence. [Illustration: FIG. 92. MONUMENT IN ST VICTOR’S, MARSEILLES.] The frequent attacks of the Saracens may also have had some influence in producing this style of exterior in the churches near the sea-coast. [Illustration: FIG. 93. ST SAUVEUR, AIX-EN-PROVENCE.] AIX-EN-PROVENCE, which is easily reached from Marseilles by a delightful railway route through the mountains, retains few marks of its distinction as the first settlement of the Romans in Gaul. A few Roman walls and pillars from the temple of Apollo, together with some fragments in the Museum, are all that Aix can shew of the original Aquæ Sextiæ. But the ancient church of St Sauveur and its octagonal baptistery exhibit the Roman influence, extending down to a comparatively late date. The baptistery is of the sixth century, but the upper portion has been restored in the style of the eighteenth century, and has thus completely lost its proper character. It is octagonal on plan, with eight monolithic granite columns taken from the ancient temple of Apollo set in the angles. [Illustration: FIG. 94. ST SAUVEUR, AIX.] The church of St Sauveur was erected in 1103, and is supposed to have been built on part of the cella of the temple of Apollo. It now forms the south aisle of the enlarged cathedral erected in the fifteenth century. But [Illustration: FIG. 95. CLOISTERS, ST SAUVEUR, AIX-EN-PROVENCE.]